The purpose of this study was to describe the ability of Manggaraian children of age six to seven in length conservation area. This research is a qualitative descriptive study. The random sampling technique was used to select 80 children, consisted of 40 children per age. The instrument of this research was a length conservation questionnaire containing statements about conditions that explain the concept of length conservation. Each child was given a length conservation skill test followed by an interview about the reasons for providing answers to the conservation test. The results showed that none of six-year-old children was conserver, only 7.5% were partial conserver, and 92.5% were non-conserver. For seven-year-old children, 7.5% were conserver, 22.5% were partial, and 70% were non-conserver. These results indicate the lengthy-term conservation ability of children age six to seven in Manggarai Regency is still low and most have not understood the concept of length conservation.

Ashley-Smith, J. (2016). Losing the edge: the risk of a decline in practical conservation skills. Journal of the Institute of Conservation, 39(2), 119–132. https://doi.org/10.1080/19455224.2016.1210015

Bobis, J. et al. (2010). Playing with mathematics: play in early childhood as a context for mathematical learning. In Shaping the future of mathematics education: Proceedings of the 33rd annual conference of the Mathematics Education Research Group of Australasia (pp. 714–730). Retrieved from https://www.researchgate.net/profile/Janette_Bobis/publication/267414818_
Playing_with_Mathematics_Play_in_Early_Childhood_as_a
_Context_for_Mathematical_Learning/links/5451270a0cf285a067c68480.pdf